H3C Technologies H3C S10500 Series Switches - Manual (Page 234)

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overwhelming the network during times of frequent changes to local device information, an interval is
introduced between two successive LLDPDUs.
This interval is shortened to 1 second in either of the following cases:
• A new neighbor is discovered. A new LLDPDU is received and carries device information new to the
local device.
• The LLDP operating mode of the port changes from Disable or Rx to TxRx or Tx.
This is the fast sending mechanism of LLDP. With this mechanism, a specific number of LLDPDUs are sent
successively at 1-second intervals, to help LLDP neighbors discover the local device as soon as possible.
Then, the normal LLDPDU transmit interval resumes.
Receiving LLDPDUs
An LLDP-enabled port that is operating in TxRx mode or Rx mode checks the validity of TLVs carried in
every received LLDPDU. If valid, the information is saved and an aging timer is set for it based on the time
to live (TTL) value in the Time to Live TLV carried in the LLDPDU. If the TTL value is zero, the information
ages out immediately.
Protocols and standards
• IEEE 802.1AB-2005, Station and Media Access Control Connectivity Discovery
• ANSI/TIA-1057, Link Layer Discovery Protocol for Media Endpoint Devices
LLDP configuration task list
Complete these tasks to configure LLDP:
Task Remarks
Enabling LLDP Required
Setting the LLDP operating mode Optional
Setting the LLDP re-initialization delay Optional
Enabling LLDP polling Optional
Configuring the advertisable TLVs Optional
Configuring the management address and its encoding format Optional
Setting other LLDP parameters Optional
Performing basic LLDP
configuration
Setting an encapsulation format for LLDPDUs Optional
Configuring CDP compatibility Optional
Configuring LLDP trapping Optional
NOTE:
•
LLDP-related configurations made in Layer 2/Layer 3 Ethernet interface view take effect only on the
current port, and those made in port group view take effect on all ports in the current port group.
• Layer 3 interfaces refer to route-mode (or Layer 3) Ethernet ports. You can set an Ethernet port to operate
in route mode by using the port link-mode route command (see the chapter “Ethernet interface
configuration”).